<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <style>
		  div {
			 position: absolute;
		  }
		  #box1{
			background: red;
			width: 200px;
			height: 200px;
		  }
		  #box2{
			background: blue;
			width: 100px;
			height: 100px;
		  }
    </style>
    <title>拖拽</title>
  </head>
<body>
    <div id="box1"></div>  
    <div id="box2"></div>
	<script src="js/Drag.js"></script>
	<script>
		new Drag('box1');
	</script>

</body>
</html>